Usain Bolt lived up to all the hype of becoming a "living legend" at the London Games, decisively defending his 100-meter title by beating Jamaican training partner Yohan Blake in the defining race of the Olympics.

He was slow out of the blocks but once he got his giant stride going he was unbeatable once again, leaving Blake and 2004 Olympic champion Justin Gatlin in his wake with the second-fastest...